High-resolution Rutherford backscattering spectroscopy (HRBS) is an excellent technique for surface analysis, that allows quantitative and non-destructive analysis with a sub-nm depth resolution within a short measurement time without any special sample preparation. While HRBS becomes popular in various research fields and industries, especially in micro-electronics industry, there are several issues which should be carefully treated for precise analysis. Principles of HRBS are discussed with particular emphasis placed on the precision of HRBS analysis. The uncertainty in HRBS analysis caused by the scattering cross sections, stopping powers and charge state distributions are discussed in detail. The overall precision of HRBS is estimated to be better than several % in both depth and concentration.